The present invention relates to a sterilization apparatus used in a water circuit of a dental chair unit. More particularly, the present invention relates to a dental treatment apparatus having a sterilized water producing unit that adjusts the residual free chlorine concentration and pH value of water used for dental treatment, and a switching controller that switches between raw water and feed water from the sterilized water producing unit.
Conventionally, during dental treatment with a dental chair unit, the patient's oral cavity is cleaned with water jets from an instrument or by using a syringe or the like. At the time of suspending the treatment, suction is used to prevent water from dripping from the tip of the instrument. At this time, disease-causing bacteria in the patient's mouth may be sucked together with water, causing the water circuit of the treatment apparatus to be contaminated.
In a case where the dental chair unit is not used for a long period of time because of the dentist's day off, for example, bacteria may propagate in water left in the water circuit.
In a case where a filter is provided in a feed circuit of the water circuit, bacteria may propagate in the filter with passage of time.
For the reasons stated above, there have heretofore been cases where contaminated water is used in a patient's mouth, and the patient is infected with disease-causing bacteria.
On the other hand, there are cases where strong acid water having a pH of 3 or below is used for sterilization. However, this technique suffers from the problem that the strong acid water remaining the water circuit oxidizes metals used in the water circuit, causing them to be rusted.